<?php //$Id: lib.php,v 1.120.2.22 2009/01/16 14:56:59 nicolasconnault Exp $

///////////////////////////////////////////////////////////////////////////
//																	   //
// NOTICE OF COPYRIGHT												   //
//																	   //
// Moodle - Modular Object-Oriented Dynamic Learning Environment		 //
//		  http://moodle.com											//
//																	   //
// Copyright (C) 1999 onwards  Martin Dougiamas  http://moodle.com	   //
//																	   //
// This program is free software; you can redistribute it and/or modify  //
// it under the terms of the GNU General Public License as published by  //
// the Free Software Foundation; either version 2 of the License, or	 //
// (at your option) any later version.								   //
//																	   //
// This program is distributed in the hope that it will be useful,	   //
// but WITHOUT ANY WARRANTY; without even the implied warranty of		//
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the		 //
// GNU General Public License for more details:						  //
//																	   //
//		  http://www.gnu.org/copyleft/gpl.html						 //
//																	   //
///////////////////////////////////////////////////////////////////////////

require_once $CFG->libdir.'/gradelib.php';

/**
 * This class iterates over all users that are graded in a course.
 * Returns detailed info about users and their grades.
 */
class graded_users_iterator {
	var $course;
	var $grade_items;
	var $groupid;
	var $users_rs;
	var $grades_rs;
	var $gradestack;
	var $sortfield1;
	var $sortorder1;
	var $sortfield2;
	var $sortorder2;

	/**
	 * Constructor
	 * @param $course object
	 * @param array grade_items array of grade items, if not specified only user info returned
	 * @param int $groupid iterate only group users if present
	 * @param string $sortfield1 The first field of the users table by which the array of users will be sorted
	 * @param string $sortorder1 The order in which the first sorting field will be sorted (ASC or DESC)
	 * @param string $sortfield2 The second field of the users table by which the array of users will be sorted
	 * @param string $sortorder2 The order in which the second sorting field will be sorted (ASC or DESC)
	 */
	function graded_users_iterator($course, $grade_items=null, $groupid=0, $sortfield1='lastname', $sortorder1='ASC', $sortfield2='firstname', $sortorder2='ASC') {
		$this->course	  = $course;
		$this->grade_items = $grade_items;
		$this->groupid	 = $groupid;
		$this->sortfield1  = $sortfield1;
		$this->sortorder1  = $sortorder1;
		$this->sortfield2  = $sortfield2;
		$this->sortorder2  = $sortorder2;

		$this->gradestack  = array();
	}

	/**
	 * Initialise the iterator
	 * @return boolean success
	 */
	function init() {
		global $CFG;

		$this->close();

		grade_regrade_final_grades($this->course->id);
		$course_item = grade_item::fetch_course_item($this->course->id);
		if ($course_item->needsupdate) {
			// can not calculate all final grades - sorry
			return false;
		}

		if (strpos($CFG->gradebookroles, ',') === false) {
			$gradebookroles = " = {$CFG->gradebookroles}";
		} else {
			$gradebookroles = " IN ({$CFG->gradebookroles})";
		}

		$relatedcontexts = get_related_contexts_string(get_context_instance(CONTEXT_COURSE, $this->course->id));

		if ($this->groupid) {
			$groupsql = "INNER JOIN {$CFG->prefix}groups_members gm ON gm.userid = u.id";
			$groupwheresql = "AND gm.groupid = {$this->groupid}";
		} else {
			$groupsql = "";
			$groupwheresql = "";
		}

		if (empty($this->sortfield1)) {
			// we must do some sorting even if not specified
			$ofields = ", u.id AS usrt";
			$order   = "usrt ASC";

		} else {
			$ofields = ", u.$this->sortfield1 AS usrt1";
			$order   = "usrt1 $this->sortorder1";
			if (!empty($this->sortfield2)) {
				$ofields .= ", u.$this->sortfield1 AS usrt2";
				$order   .= ", usrt2 $this->sortorder2";
			}
			if ($this->sortfield1 != 'id' and $this->sortfield2 != 'id') {
				// user order MUST be the same in both queries, must include the only unique user->id if not already present
				$ofields .= ", u.id AS usrt";
				$order   .= ", usrt ASC";
			}
		}

		$users_sql = "SELECT u.* $ofields
						FROM {$CFG->prefix}user u
							 INNER JOIN {$CFG->prefix}role_assignments ra ON u.id = ra.userid
							 $groupsql
					   WHERE ra.roleid $gradebookroles
							 AND ra.contextid $relatedcontexts
							 $groupwheresql
					ORDER BY $order";

		$this->users_rs = get_recordset_sql($users_sql);

		if (!empty($this->grade_items)) {
			$itemids = array_keys($this->grade_items);
			$itemids = implode(',', $itemids);

			$grades_sql = "SELECT g.* $ofields
							 FROM {$CFG->prefix}grade_grades g
								  INNER JOIN {$CFG->prefix}user u ON g.userid = u.id
								  INNER JOIN {$CFG->prefix}role_assignments ra ON u.id = ra.userid
								  $groupsql
							WHERE ra.roleid $gradebookroles
								  AND ra.contextid $relatedcontexts
								  AND g.itemid IN ($itemids)
								  $groupwheresql
						 ORDER BY $order, g.itemid ASC";
			$this->grades_rs = get_recordset_sql($grades_sql);
		} else {
			$this->grades_rs = false;
		}

		return true;
	}

	/**
	 * Returns information about the next user
	 * @return mixed array of user info, all grades and feedback or null when no more users found
	 */
	function next_user() {
		if (!$this->users_rs) {
			return false; // no users present
		}

		if (!$user = rs_fetch_next_record($this->users_rs)) {
			if ($current = $this->_pop()) {
				// this is not good - user or grades updated between the two reads above :-(
			}

			return false; // no more users
		}

		// find grades of this user
		$grade_records = array();
		while (true) {
			if (!$current = $this->_pop()) {
				break; // no more grades
			}

			if ($current->userid != $user->id) {
				// grade of the next user, we have all for this user
				$this->_push($current);
				break;
			}

			$grade_records[$current->itemid] = $current;
		}

		$grades = array();
		$feedbacks = array();

		if (!empty($this->grade_items)) {
			foreach ($this->grade_items as $grade_item) {
				if (array_key_exists($grade_item->id, $grade_records)) {
					$feedbacks[$grade_item->id]->feedback	   = $grade_records[$grade_item->id]->feedback;
					$feedbacks[$grade_item->id]->feedbackformat = $grade_records[$grade_item->id]->feedbackformat;
					unset($grade_records[$grade_item->id]->feedback);
					unset($grade_records[$grade_item->id]->feedbackformat);
					$grades[$grade_item->id] = new grade_grade($grade_records[$grade_item->id], false);
				} else {
					$feedbacks[$grade_item->id]->feedback	   = '';
					$feedbacks[$grade_item->id]->feedbackformat = FORMAT_MOODLE;
					$grades[$grade_item->id] = new grade_grade(array('userid'=>$user->id, 'itemid'=>$grade_item->id), false);
				}
			}
		}

		$result = new object();
		$result->user	  = $user;
		$result->grades	= $grades;
		$result->feedbacks = $feedbacks;

		return $result;
	}

	/**
	 * Close the iterator, do not forget to call this function.
	 * @return void
	 */
	function close() {
		if ($this->users_rs) {
			rs_close($this->users_rs);
			$this->users_rs = null;
		}
		if ($this->grades_rs) {
			rs_close($this->grades_rs);
			$this->grades_rs = null;
		}
		$this->gradestack = array();
	}

	/**
	 * Internal function
	 */
	function _push($grade) {
		array_push($this->gradestack, $grade);
	}

	/**
	 * Internal function
	 */
	function _pop() {
		if (empty($this->gradestack)) {
			if (!$this->grades_rs) {
				return NULL; // no grades present
			}

			if (!$grade = rs_fetch_next_record($this->grades_rs)) {
				return NULL; // no more grades
			}

			return $grade;
		} else {
			return array_pop($this->gradestack);
		}
	}
}

/**
 * Print a selection popup form of the graded users in a course.
 *
 * @param int $courseid id of the course
 * @param string $actionpage The page receiving the data from the popoup form
 * @param int $userid   id of the currently selected user (or 'all' if they are all selected)
 * @param bool $return If true, will return the HTML, otherwise, will print directly
 * @return null
 */
function print_graded_users_selector($course, $actionpage, $userid=null, $return=false) {
	global $CFG, $USER;

	if (is_null($userid)) {
		$userid = $USER->id;
	}

	$context = get_context_instance(CONTEXT_COURSE, $course->id);

	$menu = array(); // Will be a list of userid => user name

	$gui = new graded_users_iterator($course);
	$gui->init();

	if ($userid !== 0) {
		$menu[0] = get_string('allusers', 'grades');
	}

	while ($userdata = $gui->next_user()) {
		$user = $userdata->user;
		$menu[$user->id] = fullname($user);
	}

	$gui->close();

	if ($userid !== 0) {
		$menu[0] .= " (" . (count($menu) - 1) . ")";
	}

	return popup_form($CFG->wwwroot.'/grade/' . $actionpage . '&amp;userid=', $menu, 'choosegradeduser', $userid, 'choose', '', '',
						$return, 'self', get_string('selectalloroneuser', 'grades'));
}

/**
 * Print grading plugin selection popup form.
 *
 * @param int $courseid id of course
 * @param string $active_type type of plugin on current page - import, export, report or edit
 * @param string $active_plugin active plugin type - grader, user, cvs, ...
 * @param boolean $return return as string
 * @return nothing or string if $return true
 */
function print_grade_plugin_selector($courseid, $active_type, $active_plugin, $return=false) {
	global $CFG;

	$context = get_context_instance(CONTEXT_COURSE, $courseid);

	$menu = array();
	$count = 0;
	$active = '';

/// report plugins with its special structure
	if ($reports = get_list_of_plugins('grade/report', 'CVS')) {		 // Get all installed reports
		foreach ($reports as $key => $plugin) {					  // Remove ones we can't see
			if (!has_capability('gradereport/'.$plugin.':view', $context)) {
				unset($reports[$key]);
			}
		}
	}
	$reportnames = array();
	if (!empty($reports)) {
		foreach ($reports as $plugin) {
			$url = 'report/'.$plugin.'/index.php?id='.$courseid;
			if ($active_type == 'report' and $active_plugin == $plugin ) {
				$active = $url;
			}
			$reportnames[$url] = get_string('modulename', 'gradereport_'.$plugin);
			$count++;
		}
		asort($reportnames);
	}
	if (!empty($reportnames)) {
		$menu['reportgroup']='--'.get_string('view');
		$menu = $menu+$reportnames;
	}

/// standard import plugins
	if ($imports = get_list_of_plugins('grade/import', 'CVS')) {		 // Get all installed import plugins
		foreach ($imports as $key => $plugin) {					  // Remove ones we can't see
			if (!has_capability('gradeimport/'.$plugin.':view', $context)) {
				unset($imports[$key]);
			}
		}
	}
	$importnames = array();
	if (!empty($imports)) {
		foreach ($imports as $plugin) {
			$url = 'import/'.$plugin.'/index.php?id='.$courseid;
			if ($active_type == 'import' and $active_plugin == $plugin ) {
				$active = $url;
			}
			$importnames[$url] = get_string('modulename', 'gradeimport_'.$plugin);
			$count++;
		}
		asort($importnames);
	}
	if (!empty($importnames)) {
		$menu['importgroup']='--'.get_string('importfrom', 'grades');
		$menu = $menu+$importnames;
	}

/// standard export plugins
	if ($exports = get_list_of_plugins('grade/export', 'CVS')) {		 // Get all installed export plugins
		foreach ($exports as $key => $plugin) {					  // Remove ones we can't see
			if (!has_capability('gradeexport/'.$plugin.':view', $context)) {
				unset($exports[$key]);
			}
		}
	}
	$exportnames = array();
	if (!empty($exports)) {
		foreach ($exports as $plugin) {
			$url = 'export/'.$plugin.'/index.php?id='.$courseid;
			if ($active_type == 'export' and $active_plugin == $plugin ) {
				$active = $url;
			}
			$exportnames[$url] = get_string('modulename', 'gradeexport_'.$plugin);
			$count++;
		}
		asort($exportnames);
	}
	if (!empty($exportnames)) {
		$menu['exportgroup']='--'.get_string('exportto', 'grades');
		$menu = $menu+$exportnames;
	}

/// editing scripts - not real plugins
	if (has_capability('moodle/grade:manage', $context)
	  or has_capability('moodle/grade:manageletters', $context)
	  or has_capability('moodle/course:managescales', $context)
	  or has_capability('moodle/course:update', $context)) {
		$menu['edit']='--'.get_string('edit');

		if (has_capability('moodle/grade:manage', $context)) {
			$url = 'edit/tree/index.php?id='.$courseid;
			if ($active_type == 'edit' and $active_plugin == 'tree' ) {
				$active = $url;
			}
			$menu[$url] = get_string('edittree', 'grades');
			$count++;
		}

		if (has_capability('moodle/course:managescales', $context)) {
			$url = 'edit/scale/index.php?id='.$courseid;
			if ($active_type == 'edit' and $active_plugin == 'scale' ) {
				$active = $url;
			}
			$menu[$url] = get_string('scales');
			$count++;
		}

		if (!empty($CFG->enableoutcomes) && (has_capability('moodle/grade:manage', $context) or
											 has_capability('moodle/course:update', $context))) {
			if (has_capability('moodle/course:update', $context)) {  // Default to course assignment
				$url = 'edit/outcome/course.php?id='.$courseid;
			} else {
				$url = 'edit/outcome/index.php?id='.$courseid;
			}
			if ($active_type == 'edit' and $active_plugin == 'outcome' ) {
				$active = $url;
			}
			$menu[$url] = get_string('outcomes', 'grades');
			$count++;
		}

		if (has_capability('moodle/grade:manage', $context) or has_capability('moodle/grade:manageletters', $context)) {
			$url = 'edit/letter/index.php?id='.$courseid;
			if ($active_type == 'edit' and $active_plugin == 'letter' ) {
				$active = $url;
			}
			$menu[$url] = get_string('letters', 'grades');
			$count++;
		}

		if (has_capability('moodle/grade:manage', $context)) {
			$url = 'edit/settings/index.php?id='.$courseid;
			if ($active_type == 'edit' and $active_plugin == 'settings' ) {
				$active = $url;
			}
			$menu[$url] = get_string('coursesettings', 'grades');
			$count++;
		}

	}

/// finally print/return the popup form
	if ($count > 1) {
		return popup_form($CFG->wwwroot.'/grade/', $menu, 'choosepluginreport', '',
				get_string('chooseaction', 'grades'), '', '', $return, 'self');
	} else {
		// only one option - no plugin selector needed
		return '';
	}
}

/**
 * Utility class used for return tracking when using edit and other forms in grade plugins
 */
class grade_plugin_return {
	var $type;
	var $plugin;
	var $courseid;
	var $userid;
	var $page;

	/**
	 * Constructor
	 * @param array $params - associative array with return parameters, if null parameter are taken from _GET or _POST
	 */
	function grade_plugin_return ($params=null) {
		if (empty($params)) {
			$this->type	 = optional_param('gpr_type', null, PARAM_SAFEDIR);
			$this->plugin   = optional_param('gpr_plugin', null, PARAM_SAFEDIR);
			$this->courseid = optional_param('gpr_courseid', null, PARAM_INT);
			$this->userid   = optional_param('gpr_userid', null, PARAM_INT);
			$this->page	 = optional_param('gpr_page', null, PARAM_INT);

		} else {
			foreach ($params as $key=>$value) {
				if (array_key_exists($key, $this)) {
					$this->$key = $value;
				}
			}
		}
	}

	/**
	 * Returns return parameters as options array suitable for buttons.
	 * @return array options
	 */
	function get_options() {
		if (empty($this->type)) {
			return array();
		}

		$params = array();

		if (!empty($this->plugin)) {
			$params['plugin'] = $this->plugin;
		}

		if (!empty($this->courseid)) {
			$params['id'] = $this->courseid;
		}

		if (!empty($this->userid)) {
			$params['userid'] = $this->userid;
		}

		if (!empty($this->page)) {
			$params['page'] = $this->page;
		}

		return $params;
	}

	/**
	 * Returns return url
	 * @param string $default default url when params not set
	 * @return string url
	 */
	function get_return_url($default, $extras=null) {
		global $CFG;

		if (empty($this->type) or empty($this->plugin)) {
			return $default;
		}

		$url = $CFG->wwwroot.'/grade/'.$this->type.'/'.$this->plugin.'/index.php';
		$glue = '?';

		if (!empty($this->courseid)) {
			$url .= $glue.'id='.$this->courseid;
			$glue = '&amp;';
		}

		if (!empty($this->userid)) {
			$url .= $glue.'userid='.$this->userid;
			$glue = '&amp;';
		}

		if (!empty($this->page)) {
			$url .= $glue.'page='.$this->page;
			$glue = '&amp;';
		}

		if (!empty($extras)) {
			foreach($extras as $key=>$value) {
				$url .= $glue.$key.'='.$value;
				$glue = '&amp;';
			}
		}

		return $url;
	}

	/**
	 * Returns string with hidden return tracking form elements.
	 * @return string
	 */
	function get_form_fields() {
		if (empty($this->type)) {
			return '';
		}

		$result  = '<input type="hidden" name="gpr_type" value="'.$this->type.'" />';

		if (!empty($this->plugin)) {
			$result .= '<input type="hidden" name="gpr_plugin" value="'.$this->plugin.'" />';
		}

		if (!empty($this->courseid)) {
			$result .= '<input type="hidden" name="gpr_courseid" value="'.$this->courseid.'" />';
		}

		if (!empty($this->userid)) {
			$result .= '<input type="hidden" name="gpr_userid" value="'.$this->userid.'" />';
		}

		if (!empty($this->page)) {
			$result .= '<input type="hidden" name="gpr_page" value="'.$this->page.'" />';
		}
	}

	/**
	 * Add hidden elements into mform
	 * @param object $mform moodle form object
	 * @return void
	 */
	function add_mform_elements(&$mform) {
		if (empty($this->type)) {
			return;
		}

		$mform->addElement('hidden', 'gpr_type', $this->type);
		$mform->setType('gpr_type', PARAM_SAFEDIR);

		if (!empty($this->plugin)) {
			$mform->addElement('hidden', 'gpr_plugin', $this->plugin);
			$mform->setType('gpr_plugin', PARAM_SAFEDIR);
		}

		if (!empty($this->courseid)) {
			$mform->addElement('hidden', 'gpr_courseid', $this->courseid);
			$mform->setType('gpr_courseid', PARAM_INT);
		}

		if (!empty($this->userid)) {
			$mform->addElement('hidden', 'gpr_userid', $this->userid);
			$mform->setType('gpr_userid', PARAM_INT);
		}

		if (!empty($this->page)) {
			$mform->addElement('hidden', 'gpr_page', $this->page);
			$mform->setType('gpr_page', PARAM_INT);
		}
	}

	/**
	 * Add return tracking params into url
	 * @param string $url
	 * @return string $url with erturn tracking params
	 */
	function add_url_params($url) {
		if (empty($this->type)) {
			return $url;
		}

		if (strpos($url, '?') === false) {
			$url .= '?gpr_type='.$this->type;
		} else {
			$url .= '&amp;gpr_type='.$this->type;
		}

		if (!empty($this->plugin)) {
			$url .= '&amp;gpr_plugin='.$this->plugin;
		}

		if (!empty($this->courseid)) {
			$url .= '&amp;gpr_courseid='.$this->courseid;
		}

		if (!empty($this->userid)) {
			$url .= '&amp;gpr_userid='.$this->userid;
		}

		if (!empty($this->page)) {
			$url .= '&amp;gpr_page='.$this->page;
		}

		return $url;
	}
}

/**
 * Function central to gradebook for building and printing the navigation (breadcrumb trail).
 * @param string $path The path of the calling script (using __FILE__?)
 * @param string $pagename The language string to use as the last part of the navigation (non-link)
 * @param mixed  $id Either a plain integer (assuming the key is 'id') or an array of keys and values (e.g courseid => $courseid, itemid...)
 * @return string
 */
function grade_build_nav($path, $pagename=null, $id=null) {
	global $CFG, $COURSE;

	$strgrades = get_string('grades', 'grades');

	// Parse the path and build navlinks from its elements
	$dirroot_length = strlen($CFG->dirroot) + 1; // Add 1 for the first slash
	$path = substr($path, $dirroot_length);
	$path = str_replace('\\', '/', $path);

	$path_elements = explode('/', $path);

	$path_elements_count = count($path_elements);

	// First link is always 'grade'
	$navlinks = array();
	$navlinks[] = array('name' => $strgrades,
						'link' => $CFG->wwwroot.'/grade/index.php?id='.$COURSE->id,
						'type' => 'misc');

	$link = '';
	$numberofelements = 3;

	// Prepare URL params string
	$id_string = '?';
	if (!is_null($id)) {
		if (is_array($id)) {
			foreach ($id as $idkey => $idvalue) {
				$id_string .= "$idkey=$idvalue&amp;";
			}
		} else {
			$id_string .= "id=$id";
		}
	}

	$navlink4 = null;

	// Remove file extensions from filenames
	foreach ($path_elements as $key => $filename) {
		$path_elements[$key] = str_replace('.php', '', $filename);
	}

	// Second level links
	switch ($path_elements[1]) {
		case 'edit': // No link
			if ($path_elements[3] != 'index.php') {
				$numberofelements = 4;
			}
			break;
		case 'import': // No link
			break;
		case 'export': // No link
			break;
		case 'report':
			// $id is required for this link. Do not print it if $id isn't given
			if (!is_null($id)) {
				$link = $CFG->wwwroot . '/grade/report/index.php' . $id_string;
			}

			if ($path_elements[2] == 'grader') {
				$numberofelements = 4;
			}
			break;

		default:
			// If this element isn't among the ones already listed above, it isn't supported, throw an error.
			debugging("grade_build_nav() doesn't support ". $path_elements[1] . " as the second path element after 'grade'.");
			return false;
	}

	$navlinks[] = array('name' => get_string($path_elements[1], 'grades'), 'link' => $link, 'type' => 'misc');

	// Third level links
	if (empty($pagename)) {
		$pagename = get_string($path_elements[2], 'grades');
	}

	switch ($numberofelements) {
		case 3:
			$navlinks[] = array('name' => $pagename, 'link' => $link, 'type' => 'misc');
			break;
		case 4:

			if ($path_elements[2] == 'grader' AND $path_elements[3] != 'index.php') {
				$navlinks[] = array('name' => get_string('modulename', 'gradereport_grader'),
									'link' => "$CFG->wwwroot/grade/report/grader/index.php$id_string",
									'type' => 'misc');
			}
			$navlinks[] = array('name' => $pagename, 'link' => '', 'type' => 'misc');
			break;
	}
	$navigation = build_navigation($navlinks);

	return $navigation;
}

/**
 * General structure representing grade items in course
 */
class grade_structure {
	var $context;

	var $courseid;

	/**
	 * 1D array of grade items only
	 */
	var $items;

	/**
	 * Returns icon of element
	 * @param object $element
	 * @param bool $spacerifnone return spacer if no icon found
	 * @return string icon or spacer
	 */
	function get_element_icon(&$element, $spacerifnone=false) {
		global $CFG;

		switch ($element['type']) {
			case 'item':
			case 'courseitem':
			case 'categoryitem':
				if ($element['object']->is_calculated()) {
					return '<img src="'.$CFG->pixpath.'/i/calc.gif" class="icon itemicon" alt="'.get_string('calculation', 'grades').'"/>';

				} else if (($element['object']->is_course_item() or $element['object']->is_category_item())
				  and ($element['object']->gradetype == GRADE_TYPE_SCALE or $element['object']->gradetype == GRADE_TYPE_VALUE)) {
					if ($category = $element['object']->get_item_category()) {
						switch ($category->aggregation) {
							case GRADE_AGGREGATE_MEAN:
							case GRADE_AGGREGATE_MEDIAN:
							case GRADE_AGGREGATE_WEIGHTED_MEAN:
							case GRADE_AGGREGATE_WEIGHTED_MEAN2:
							case GRADE_AGGREGATE_EXTRACREDIT_MEAN:
								return '<img src="'.$CFG->pixpath.'/i/agg_mean.gif" class="icon itemicon" alt="'.get_string('aggregation', 'grades').'"/>';
							case GRADE_AGGREGATE_SUM:
								return '<img src="'.$CFG->pixpath.'/i/agg_sum.gif" class="icon itemicon" alt="'.get_string('aggregation', 'grades').'"/>';
						}
					}

				} else if ($element['object']->itemtype == 'mod') {
					return '<img src="'.$CFG->modpixpath.'/'.$element['object']->itemmodule.'/icon.gif" class="icon itemicon" alt="'
						   .get_string('modulename', $element['object']->itemmodule).'"/>';

				} else if ($element['object']->itemtype == 'manual') {
					if ($element['object']->is_outcome_item()) {
						return '<img src="'.$CFG->pixpath.'/i/outcomes.gif" class="icon itemicon" alt="'.get_string('outcome', 'grades').'"/>';
					} else {
						return '<img src="'.$CFG->pixpath.'/t/manual_item.gif" class="icon itemicon" alt="'.get_string('manualitem', 'grades').'"/>';
					}
				}
				break;

			case 'category':
				return '<img src="'.$CFG->pixpath.'/f/folder.gif" class="icon itemicon" alt="'.get_string('category', 'grades').'"/>';
		}

		if ($spacerifnone) {
			return '<img src="'.$CFG->wwwroot.'/pix/spacer.gif" class="icon itemicon" alt=""/>';
		} else {
			return '';
		}
	}

	/**
	 * Returns name of element optionally with icon and link
	 * @param object $element
	 * @param bool $withlinks
	 * @param bool $icons
	 * @param bool $spacerifnone return spacer if no icon found
	 * @return header string
	 */
	function get_element_header(&$element, $withlink=false, $icon=true, $spacerifnone=false) {
		global $CFG;

		$header = '';

		if ($icon) {
			$header .= $this->get_element_icon($element, $spacerifnone);
		}

		$title = $element['object']->get_name();
		$header .= $title;

		if ($element['type'] != 'item' and $element['type'] != 'categoryitem' and $element['type'] != 'courseitem') {
			return $header;
		}

		$itemtype	 = $element['object']->itemtype;
		$itemmodule   = $element['object']->itemmodule;
		$iteminstance = $element['object']->iteminstance;

		if ($withlink and $itemtype=='mod' and $iteminstance and $itemmodule) {
			if ($cm = get_coursemodule_from_instance($itemmodule, $iteminstance, $this->courseid)) {

				$dir = $CFG->dirroot.'/mod/'.$itemmodule;

				if (file_exists($dir.'/grade.php')) {
					$url = $CFG->wwwroot.'/mod/'.$itemmodule.'/grade.php?id='.$cm->id;
				} else {
					$url = $CFG->wwwroot.'/mod/'.$itemmodule.'/view.php?id='.$cm->id;
				}

				$header = '<a href="'.$url.'" title="'.$title.'">'.$header.'</a>';
			}
		}

		return $header;
	}

	/**
	 * Returns the grade eid - the grade may not exist yet.
	 * @param $grade_grade object
	 * @return string eid
	 */
	function get_grade_eid($grade_grade) {
		if (empty($grade_grade->id)) {
			return 'n'.$grade_grade->itemid.'u'.$grade_grade->userid;
		} else {
			return 'g'.$grade_grade->id;
		}
	}

	/**
	 * Returns the grade_item eid
	 * @param $grade_item object
	 * @return string eid
	 */
	function get_item_eid($grade_item) {
		return 'i'.$grade_item->id;
	}

	function get_params_for_iconstr($element) {
		$strparams = new stdClass();
		$strparams->category = '';
		$strparams->itemname = '';
		$strparams->itemmodule = '';
		if (!method_exists($element['object'], 'get_name')) {
			return $strparams;
		}

		$strparams->itemname = $element['object']->get_name();

		// If element name is categorytotal, get the name of the parent category
		if ($strparams->itemname == get_string('categorytotal', 'grades')) {
			$parent = $element['object']->get_parent_category();
			$strparams->category = $parent->get_name() . ' ';
		} else {
			$strparams->category = '';
		}

		$strparams->itemmodule = null;
		if (isset($element['object']->itemmodule)) {
			$strparams->itemmodule = $element['object']->itemmodule;
		}
		return $strparams;
	}

	/**
	 * Return edit icon for give element
	 * @param object $element
	 * @return string
	 */
	function get_edit_icon($element, $gpr) {
		global $CFG;

		if (!has_capability('moodle/grade:manage', $this->context)) {
			if ($element['type'] == 'grade' and has_capability('moodle/grade:edit', $this->context)) {
				// oki - let them override grade
			} else {
				return '';
			}
		}

		static $strfeedback   = null;
		static $streditgrade = null;
		if (is_null($streditgrade)) {
			$streditgrade = get_string('editgrade', 'grades');
			$strfeedback  = get_string('feedback');
		}

		$strparams = $this->get_params_for_iconstr($element);
		if ($element['type'] == 'item' or $element['type'] == 'category') {
		}

		$object = $element['object'];
		$overlib = '';

		switch ($element['type']) {
			case 'item':
			case 'categoryitem':
			case 'courseitem':
				$stredit = get_string('editverbose', 'grades', $strparams);
				if (empty($object->outcomeid) || empty($CFG->enableoutcomes)) {
					$url = $CFG->wwwroot.'/grade/edit/tree/item.php?courseid='.$this->courseid.'&amp;id='.$object->id;
				} else {
					$url = $CFG->wwwroot.'/grade/edit/tree/outcomeitem.php?courseid='.$this->courseid.'&amp;id='.$object->id;
				}
				$url = $gpr->add_url_params($url);
				break;

			case 'category':
				$stredit = get_string('editverbose', 'grades', $strparams);
				$url = $CFG->wwwroot.'/grade/edit/tree/category.php?courseid='.$this->courseid.'&amp;id='.$object->id;
				$url = $gpr->add_url_params($url);
				break;

			case 'grade':
				$stredit = $streditgrade;
				if (empty($object->id)) {
					$url = $CFG->wwwroot.'/grade/edit/tree/grade.php?courseid='.$this->courseid.'&amp;itemid='.$object->itemid.'&amp;userid='.$object->userid;
				} else {
					$url = $CFG->wwwroot.'/grade/edit/tree/grade.php?courseid='.$this->courseid.'&amp;id='.$object->id;
				}
				$url = $gpr->add_url_params($url);
				if (!empty($object->feedback)) {
					$feedback = addslashes_js(trim(format_string($object->feedback, $object->feedbackformat)));
					$function = "return overlib('$feedback', BORDER, 0, FGCLASS, 'feedback', "
							  ."CAPTIONFONTCLASS, 'caption', CAPTION, '$strfeedback');";
					$overlib = 'onmouseover="'.s($function).'" onmouseout="return nd();"';
				}
				break;

			default:
				$url = null;
		}

		if ($url) {
			return '<a href="'.$url.'"><img '.$overlib.' src="'.$CFG->pixpath.'/t/edit.gif" class="iconsmall" alt="'.$stredit.'" title="'.$stredit.'"/></a>';

		} else {
			return '';
		}
	}

	/**
	 * Return hiding icon for give element
	 * @param object $element
	 * @return string
	 */
	function get_hiding_icon($element, $gpr) {
		global $CFG;

		if (!has_capability('moodle/grade:manage', $this->context) and !has_capability('moodle/grade:hide', $this->context)) {
			return '';
		}

		$strparams = $this->get_params_for_iconstr($element);
		$strshow = get_string('showverbose', 'grades', $strparams);
		$strhide = get_string('hideverbose', 'grades', $strparams);

		if ($element['object']->is_hidden()) {
			$icon = 'show';
			$tooltip = $strshow;

			if ($element['type'] != 'category' and $element['object']->get_hidden() > 1) { // Change the icon and add a tooltip showing the date
				$icon = 'hiddenuntil';
				$tooltip = get_string('hiddenuntildate', 'grades', userdate($element['object']->get_hidden()));
			}

			$url	 = $CFG->wwwroot.'/grade/edit/tree/action.php?id='.$this->courseid.'&amp;action=show&amp;sesskey='.sesskey()
					 . '&amp;eid='.$element['eid'];
			$url	 = $gpr->add_url_params($url);
			$action  = '<a href="'.$url.'"><img alt="'.$strshow.'" src="'.$CFG->pixpath.'/t/'.$icon.'.gif" class="iconsmall" title="'.$tooltip.'"/></a>';

		} else {
			$url	 = $CFG->wwwroot.'/grade/edit/tree/action.php?id='.$this->courseid.'&amp;action=hide&amp;sesskey='.sesskey()
					 . '&amp;eid='.$element['eid'];
			$url	 = $gpr->add_url_params($url);
			$action  = '<a href="'.$url.'"><img src="'.$CFG->pixpath.'/t/hide.gif" class="iconsmall" alt="'.$strhide.'" title="'.$strhide.'"/></a>';
		}
		return $action;
	}

	/**
	 * Return locking icon for given element
	 * @param object $element
	 * @return string
	 */
	function get_locking_icon($element, $gpr) {
		global $CFG;

		$strparams = $this->get_params_for_iconstr($element);
		$strunlock = get_string('unlockverbose', 'grades', $strparams);
		$strlock = get_string('lockverbose', 'grades', $strparams);

		// Don't allow an unlocking action for a grade whose grade item is locked: just print a state icon
		if ($element['type'] == 'grade' && $element['object']->grade_item->is_locked()) {
			$strparamobj = new stdClass();
			$strparamobj->itemname = $element['object']->grade_item->itemname;
			$strnonunlockable = get_string('nonunlockableverbose', 'grades', $strparamobj);
			$action  = '<img src="'.$CFG->pixpath.'/t/unlock_gray.gif" alt="'.$strnonunlockable.'" class="iconsmall" title="'.$strnonunlockable.'"/>';
		} elseif ($element['object']->is_locked()) {
			$icon = 'unlock';
			$tooltip = $strunlock;

			if ($element['type'] != 'category' and $element['object']->get_locktime() > 1) { // Change the icon and add a tooltip showing the date
				$icon = 'locktime';
				$tooltip = get_string('locktimedate', 'grades', userdate($element['object']->get_locktime()));
			}

			if (!has_capability('moodle/grade:manage', $this->context) and !has_capability('moodle/grade:unlock', $this->context)) {
				return '';
			}
			$url	 = $CFG->wwwroot.'/grade/edit/tree/action.php?id='.$this->courseid.'&amp;action=unlock&amp;sesskey='.sesskey()
					 . '&amp;eid='.$element['eid'];
			$url	 = $gpr->add_url_params($url);
			$action  = '<a href="'.$url.'"><img src="'.$CFG->pixpath.'/t/'.$icon.'.gif" alt="'.$strunlock.'" class="iconsmall" title="'.$tooltip.'"/></a>';

		} else {
			if (!has_capability('moodle/grade:manage', $this->context) and !has_capability('moodle/grade:lock', $this->context)) {
				return '';
			}
			$url	 = $CFG->wwwroot.'/grade/edit/tree/action.php?id='.$this->courseid.'&amp;action=lock&amp;sesskey='.sesskey()
					 . '&amp;eid='.$element['eid'];
			$url	 = $gpr->add_url_params($url);
			$action  = '<a href="'.$url.'"><img src="'.$CFG->pixpath.'/t/lock.gif" class="iconsmall" alt="'.$strlock.'" title="'
					 . $strlock.'"/></a>';
		}
		return $action;
	}

	/**
	 * Return calculation icon for given element
	 * @param object $element
	 * @return string
	 */
	function get_calculation_icon($element, $gpr) {
		global $CFG;
		if (!has_capability('moodle/grade:manage', $this->context)) {
			return '';
		}

		$calculation_icon = '';

		$type   = $element['type'];
		$object = $element['object'];


		if ($type == 'item' or $type == 'courseitem' or $type == 'categoryitem') {
			$strparams = $this->get_params_for_iconstr($element);
			$streditcalculation = get_string('editcalculationverbose', 'grades', $strparams);

			// show calculation icon only when calculation possible
			if (!$object->is_external_item() and ($object->gradetype == GRADE_TYPE_SCALE or $object->gradetype == GRADE_TYPE_VALUE)) {
				if ($object->is_calculated()) {
					$icon = 'calc.gif';
				} else {
					$icon = 'calc_off.gif';
				}
				$url = $CFG->wwwroot.'/grade/edit/tree/calculation.php?courseid='.$this->courseid.'&amp;id='.$object->id;
				$url = $gpr->add_url_params($url);
				$calculation_icon = '<a href="'. $url.'"><img src="'.$CFG->pixpath.'/t/'.$icon.'" class="iconsmall" alt="'
									   . $streditcalculation.'" title="'.$streditcalculation.'" /></a>'. "\n";
			}
		}

		return $calculation_icon;
	}
}

/**
 * Flat structure similar to grade tree.
 */
class grade_seq extends grade_structure {

	/**
	 * A string of GET URL variables, namely courseid and sesskey, used in most URLs built by this class.
	 * @var string $commonvars
	 */
	var $commonvars;

	/**
	 * 1D array of elements
	 */
	var $elements;

	/**
	 * Constructor, retrieves and stores array of all grade_category and grade_item
	 * objects for the given courseid. Full objects are instantiated. Ordering sequence is fixed if needed.
	 * @param int $courseid
	 * @param boolean $category_grade_last category grade item is the last child
	 * @param array $collapsed array of collapsed categories
	 */
	function grade_seq($courseid, $category_grade_last=false, $nooutcomes=false) {
		global $USER, $CFG;

		$this->courseid   = $courseid;
		$this->commonvars = "&amp;sesskey=$USER->sesskey&amp;id=$this->courseid";
		$this->context	= get_context_instance(CONTEXT_COURSE, $courseid);

		// get course grade tree
		$top_element = grade_category::fetch_course_tree($courseid, true);

		$this->elements = grade_seq::flatten($top_element, $category_grade_last, $nooutcomes);

		foreach ($this->elements as $key=>$unused) {
			$this->items[$this->elements[$key]['object']->id] =& $this->elements[$key]['object'];
		}
	}

	/**
	 * Static recursive helper - makes the grade_item for category the last children
	 * @static
	 * @param array $element The seed of the recursion
	 * @return void
	 */
	function flatten(&$element, $category_grade_last, $nooutcomes) {
		if (empty($element['children'])) {
			return array();
		}
		$children = array();

		foreach ($element['children'] as $sortorder=>$unused) {
			if ($nooutcomes and $element['type'] != 'category' and $element['children'][$sortorder]['object']->is_outcome_item()) {
				continue;
			}
			$children[] = $element['children'][$sortorder];
		}
		unset($element['children']);

		if ($category_grade_last and count($children) > 1) {
			$cat_item = array_shift($children);
			array_push($children, $cat_item);
		}

		$result = array();
		foreach ($children as $child) {
			if ($child['type'] == 'category') {
				$result = $result + grade_seq::flatten($child, $category_grade_last, $nooutcomes);
			} else {
				$child['eid'] = 'i'.$child['object']->id;
				$result[$child['object']->id] = $child;
			}
		}

		return $result;
	}

	/**
	 * Parses the array in search of a given eid and returns a element object with
	 * information about the element it has found.
	 * @param int $eid
	 * @return object element
	 */
	function locate_element($eid) {
		// it is a grade - construct a new object
		if (strpos($eid, 'n') === 0) {
			if (!preg_match('/n(\d+)u(\d+)/', $eid, $matches)) {
				return null;
			}

			$itemid = $matches[1];
			$userid = $matches[2];

			//extra security check - the grade item must be in this tree
			if (!$item_el = $this->locate_element('i'.$itemid)) {
				return null;
			}

			// $gradea->id may be null - means does not exist yet
			$grade = new grade_grade(array('itemid'=>$itemid, 'userid'=>$userid));

			$grade->grade_item =& $item_el['object']; // this may speedup grade_grade methods!
			return array('eid'=>'n'.$itemid.'u'.$userid,'object'=>$grade, 'type'=>'grade');

		} else if (strpos($eid, 'g') === 0) {
			$id = (int)substr($eid, 1);
			if (!$grade = grade_grade::fetch(array('id'=>$id))) {
				return null;
			}
			//extra security check - the grade item must be in this tree
			if (!$item_el = $this->locate_element('i'.$grade->itemid)) {
				return null;
			}
			$grade->grade_item =& $item_el['object']; // this may speedup grade_grade methods!
			return array('eid'=>'g'.$id,'object'=>$grade, 'type'=>'grade');
		}

		// it is a category or item
		foreach ($this->elements as $element) {
			if ($element['eid'] == $eid) {
				return $element;
			}
		}

		return null;
	}
}

/**
 * This class represents a complete tree of categories, grade_items and final grades,
 * organises as an array primarily, but which can also be converted to other formats.
 * It has simple method calls with complex implementations, allowing for easy insertion,
 * deletion and moving of items and categories within the tree.
 */
class grade_tree extends grade_structure {

	/**
	 * The basic representation of the tree as a hierarchical, 3-tiered array.
	 * @var object $top_element
	 */
	var $top_element;

	/**
	 * A string of GET URL variables, namely courseid and sesskey, used in most URLs built by this class.
	 * @var string $commonvars
	 */
	var $commonvars;

	/**
	 * 2D array of grade items and categories
	 */
	var $levels;

	/**
	 * Grade items
	 */
	var $items;

	/**
	 * Constructor, retrieves and stores a hierarchical array of all grade_category and grade_item
	 * objects for the given courseid. Full objects are instantiated. Ordering sequence is fixed if needed.
	 * @param int $courseid
	 * @param boolean $fillers include fillers and colspans, make the levels var "rectangular"
	 * @param boolean $category_grade_last category grade item is the last child
	 * @param array $collapsed array of collapsed categories
	 */
	function grade_tree($courseid, $fillers=true, $category_grade_last=false, $collapsed=null, $nooutcomes=false) {
		global $USER, $CFG;

		$this->courseid   = $courseid;
		$this->commonvars = "&amp;sesskey=$USER->sesskey&amp;id=$this->courseid";
		$this->levels	 = array();
		$this->context	= get_context_instance(CONTEXT_COURSE, $courseid);

		// get course grade tree
		$this->top_element = grade_category::fetch_course_tree($courseid, true);

		// collapse the categories if requested
		if (!empty($collapsed)) {
			grade_tree::category_collapse($this->top_element, $collapsed);
		}

		// no otucomes if requested
		if (!empty($nooutcomes)) {
			grade_tree::no_outcomes($this->top_element);
		}

		// move category item to last position in category
		if ($category_grade_last) {
			grade_tree::category_grade_last($this->top_element);
		}

		if ($fillers) {
			// inject fake categories == fillers
			grade_tree::inject_fillers($this->top_element, 0);
			// add colspans to categories and fillers
			grade_tree::inject_colspans($this->top_element);
		}

		grade_tree::fill_levels($this->levels, $this->top_element, 0);

	}

	/**
	 * Static recursive helper - removes items from collapsed categories
	 * @static
	 * @param array $element The seed of the recursion
	 * @param array $collapsed array of collapsed categories
	 * @return void
	 */
	function category_collapse(&$element, $collapsed) {
		if ($element['type'] != 'category') {
			return;
		}
		if (empty($element['children']) or count($element['children']) < 2) {
			return;
		}

		if (in_array($element['object']->id, $collapsed['aggregatesonly'])) {
			$category_item = reset($element['children']); //keep only category item
			$element['children'] = array(key($element['children'])=>$category_item);

		} else {
			if (in_array($element['object']->id, $collapsed['gradesonly'])) { // Remove category item
				reset($element['children']);
				$first_key = key($element['children']);
				unset($element['children'][$first_key]);
			}
			foreach ($element['children'] as $sortorder=>$child) { // Recurse through the element's children
				grade_tree::category_collapse($element['children'][$sortorder], $collapsed);
			}
		}
	}

	/**
	 * Static recursive helper - removes all outcomes
	 * @static
	 * @param array $element The seed of the recursion
	 * @return void
	 */
	function no_outcomes(&$element) {
		if ($element['type'] != 'category') {
			return;
		}
		foreach ($element['children'] as $sortorder=>$child) {
			if ($element['children'][$sortorder]['type'] == 'item'
			  and $element['children'][$sortorder]['object']->is_outcome_item()) {
				unset($element['children'][$sortorder]);

			} else if ($element['children'][$sortorder]['type'] == 'category') {
				grade_tree::no_outcomes($element['children'][$sortorder]);
			}
		}
	}

	/**
	 * Static recursive helper - makes the grade_item for category the last children
	 * @static
	 * @param array $element The seed of the recursion
	 * @return void
	 */
	function category_grade_last(&$element) {
		if (empty($element['children'])) {
			return;
		}
		if (count($element['children']) < 2) {
			return;
		}
		$first_item = reset($element['children']);
		if ($first_item['type'] == 'categoryitem' or $first_item['type'] == 'courseitem') {
			// the category item might have been already removed
			$order = key($element['children']);
			unset($element['children'][$order]);
			$element['children'][$order] =& $first_item;
		}
		foreach ($element['children'] as $sortorder => $child) {
			grade_tree::category_grade_last($element['children'][$sortorder]);
		}
	}

	/**
	 * Static recursive helper - fills the levels array, useful when accessing tree elements of one level
	 * @static
	 * @param int $levels
	 * @param array $element The seed of the recursion
	 * @param int $depth
	 * @return void
	 */
	function fill_levels(&$levels, &$element, $depth) {
		if (!array_key_exists($depth, $levels)) {
			$levels[$depth] = array();
		}

		// prepare unique identifier
		if ($element['type'] == 'category') {
			$element['eid'] = 'c'.$element['object']->id;
		} else if (in_array($element['type'], array('item', 'courseitem', 'categoryitem'))) {
			$element['eid'] = 'i'.$element['object']->id;
			$this->items[$element['object']->id] =& $element['object'];
		}

		$levels[$depth][] =& $element;
		$depth++;
		if (empty($element['children'])) {
			return;
		}
		$prev = 0;
		foreach ($element['children'] as $sortorder=>$child) {
			grade_tree::fill_levels($levels, $element['children'][$sortorder], $depth);
			$element['children'][$sortorder]['prev'] = $prev;
			$element['children'][$sortorder]['next'] = 0;
			if ($prev) {
				$element['children'][$prev]['next'] = $sortorder;
			}
			$prev = $sortorder;
		}
	}

	/**
	 * Static recursive helper - makes full tree (all leafes are at the same level)
	 */
	function inject_fillers(&$element, $depth) {
		$depth++;

		if (empty($element['children'])) {
			return $depth;
		}
		$chdepths = array();
		$chids = array_keys($element['children']);
		$last_child  = end($chids);
		$first_child = reset($chids);

		foreach ($chids as $chid) {
			$chdepths[$chid] = grade_tree::inject_fillers($element['children'][$chid], $depth);
		}
		arsort($chdepths);

		$maxdepth = reset($chdepths);
		foreach ($chdepths as $chid=>$chd) {
			if ($chd == $maxdepth) {
				continue;
			}
			for ($i=0; $i < $maxdepth-$chd; $i++) {
				if ($chid == $first_child) {
					$type = 'fillerfirst';
				} else if ($chid == $last_child) {
					$type = 'fillerlast';
				} else {
					$type = 'filler';
				}
				$oldchild =& $element['children'][$chid];
				$element['children'][$chid] = array('object'=>'filler', 'type'=>$type, 'eid'=>'', 'depth'=>$element['object']->depth,'children'=>array($oldchild));
			}
		}

		return $maxdepth;
	}

	/**
	 * Static recursive helper - add colspan information into categories
	 */
	function inject_colspans(&$element) {
		if (empty($element['children'])) {
			return 1;
		}
		$count = 0;
		foreach ($element['children'] as $key=>$child) {
			$count += grade_tree::inject_colspans($element['children'][$key]);
		}
		$element['colspan'] = $count;
		return $count;
	}

	/**
	 * Parses the array in search of a given eid and returns a element object with
	 * information about the element it has found.
	 * @param int $eid
	 * @return object element
	 */
	function locate_element($eid) {
		// it is a grade - construct a new object
		if (strpos($eid, 'n') === 0) {
			if (!preg_match('/n(\d+)u(\d+)/', $eid, $matches)) {
				return null;
			}

			$itemid = $matches[1];
			$userid = $matches[2];

			//extra security check - the grade item must be in this tree
			if (!$item_el = $this->locate_element('i'.$itemid)) {
				return null;
			}

			// $gradea->id may be null - means does not exist yet
			$grade = new grade_grade(array('itemid'=>$itemid, 'userid'=>$userid));

			$grade->grade_item =& $item_el['object']; // this may speedup grade_grade methods!
			return array('eid'=>'n'.$itemid.'u'.$userid,'object'=>$grade, 'type'=>'grade');

		} else if (strpos($eid, 'g') === 0) {
			$id = (int)substr($eid, 1);
			if (!$grade = grade_grade::fetch(array('id'=>$id))) {
				return null;
			}
			//extra security check - the grade item must be in this tree
			if (!$item_el = $this->locate_element('i'.$grade->itemid)) {
				return null;
			}
			$grade->grade_item =& $item_el['object']; // this may speedup grade_grade methods!
			return array('eid'=>'g'.$id,'object'=>$grade, 'type'=>'grade');
		}

		// it is a category or item
		foreach ($this->levels as $row) {
			foreach ($row as $element) {
				if ($element['type'] == 'filler') {
					continue;
				}
				if ($element['eid'] == $eid) {
					return $element;
				}
			}
		}

		return null;
	}
}

?>
